?DESCRIPTION (provided by applicant): The Einstein Aging Study (EAS) has long focused on the risk factors and cognitive changes that predict the subsequent onset of dementia, particularly Alzheimer's dementia (AD). Traditional diagnostic approaches measure cognition on single occasions. Yet, cognitive performance may vary within individuals over hours or days, resulting in single shot assessments that are influenced by unmeasured sources of within-person variability. The limited reliability, precision and ecological validity of standard assessment approaches impedes the sensitive measurement of cognitive status and change, delaying the detection of the earliest cognitive impairment in preclinical AD. The overall goal of this competing renewal is to use ambulatory methods to improve the detection and definition of the cognitive states associated with preclinical AD and to better characterize the role of novel and remediable risk factors on the preclinical onset of AD. The EAS will address these problems by leveraging recent innovations in the use of ambulatory methods. Our team has developed ambulatory methods that use mobile technology (e.g., smartphones) to assess both objective and subjective cognitive function, behavior, and psychological states in real-time and in people's naturalistic settings. The EAS has long been a community-based study; with this new proposal, we move from bringing the community into our clinic to bringing our clinic-developed measures directly to the community. We will combine these novel ambulatory cognitive measures with the team's expertise in assessing vascular function and risk factors, as well as pain and stress as they relate to cognitive health. By integrating ambulatory measurement of cognitive function (Project 3), stress and pain (Project 1) and autonomic function (Project 2), we will be able to elucidate the biological, behavioral and psychological processes that impact daily cognitive function and long-term cognitive decline. We are enthusiastic to explore the use of ambulatory assessments acquired in an individual's natural environment to improve the ecological validity of cognitive research by enhancing researchers' ability to study cognitive function and pre-clinical AD in older adults. This work will lead to a better understanding of cognitive aging and dementia and ultimately set the stage for intervention studies.